1. Field of the Invention
The present invention relates to a leader block rotating mechanism of a cartridge magnetic tape drive.
2. Description of the Related Art
For example, Patent Document 1 discloses a leader block rotating mechanism of a cartridge magnetic tape drive which captures or releases a leader pin of a magnetic tape by rotating a leader block.
FIGS. 1 and 2 show a configuration of a conventional leader block rotating mechanism disclosed in Patent Document 1 and FIGS. 3 and 4 show its working principle. FIG. 3 shows the leader block rotating mechanism from the upside and FIG. 4 shows it from the downside. Moreover, FIG. 5 shows a schematic configuration of the conventional cartridge magnetic tape drive disclosed in Patent Document 1.
As shown in FIGS. 1 and 2, the conventional leader block rotating mechanism is engaged with a protrusion 1014a of a retractor table 1014 on which a groove 1013a of a leader block 1013 freely rotates while the leader block 1013 is moved and positioned at a capture position.
Then, as shown in FIGS. 3A to 3C and FIGS. 4A to 4C, to capture the leader pin of the magnetic tape by the leader block 1013, a linear motion of a retractor cam 1015 is converted into the rotational motion of the retractor table 1014 by pressing the retractor table 1014 in X direction in FIGS. 3 and 4 by the retractor cam 1015 in the case of the conventional leader block rotating mechanism. Moreover, the leader block 1013 engaged with the retractor table 1014 rotates to capture the leader pin of the magnetic tape by a hook portion 1013b of the leader block 1013.
Moreover, to release the leader pin from the hook portion 1013b, the operation reverse to the above operation is performed. That is, the retractor cam 1015 moves in the opposite direction and the leader block 1013 is rotated by the tension of a spring 1016 rotating the leader block 1013 in the release direction. Then, the hook portion 1013b of the leader block 1013 is removed from the leader pin of the magnetic tape.
By referring to FIGS. 5A and 5B, how the leader block 1013 operates in the conventional cartridge magnetic tape drive disclosed in Patent Document 1 is briefly described below.
As shown in FIG. 5A, when a cartridge 1001 is inserted into a cartridge loader 1004, a loader drive gear 1006 receives a required driving force (driving source is not illustrated) to rotate in the direction of the arrow A. Then, the cartridge loader 1004 linearly moves in the direction of the arrow X to load the cartridge 1001 to a predetermined loading position. However, a threader drive gear 1007 rotates in the direction of the arrow B in accordance with the rotation of the loader drive gear 1006.
When the loader drive gear 1006 further rotates in the direction of the arrow A, the cartridge loader 1004 further slides in the direction of the arrow X. In this case, the retractor cam 1015 (refer to FIG. 3) thrust to the downside of the cartridge loader 1004 presses the retractor pin 1014b (refer to FIG. 2) in the direction of the arrow X. Therefore, the retractor table 1014 rotates in the direction of the arrow Y shown in FIGS. 3 and 4 by using a pivoted axis (not illustrated) as a fulcrum.
In this case, because the protrusion 1014a and groove 1013c are fitted, the leader block 1013 is also rotated in accordance with the rotation of the retractor table 1014. Then, the leader block 1013 is led to the table vent of the cartridge 1001. A state is realized in which the hook 1013b is engaged with the leader pin 1001a and held from the rear side of the loading direction.
In the case of the above prior art, however, the rotation angle of the leader block 1013 depends on the slide stroke of the retractor cam 1015. Therefore, miscapture of the leader pin or a mechanism component may be broken due to excessive or insufficient rotation of the leader block 1013 depending on adjustment of the slide stroke of the retractor cam 1015. The cartridge loader 1004 to which the retractor cam 1015 is constituted so as to move when the rotational motion of the loader drive gear 1006 in the direction of the arrow A due to a not-illustrated driving source is converted into a linear motion in the direction of the arrow X. Therefore, when considering the “play” of the conversion mechanism, it is difficult to keep the slide stroke of the retractor cam 1015 constant. Therefore, miscapture of the leader pin may occur due to excessive or insufficient rotation of the leader block 1013 depending on operation states of these mechanisms.
Therefore, the present applicant proposes a leader block rotating mechanism of a cartridge magnetic tape drive making it possible to prevent miscapture of a leader pin due to excessive or insufficient rotation of a leader block in Patent Document 2.
By referring to FIGS. 6 to 10, the capture operation of a leader pin by the leader block rotating mechanism disclosed on the Patent Document 2 is described below.
As shown in FIG. 6, when a cartridge (not illustrated) is inserted into a cartridge magnetic tape drive, a motor 2006 is driven and a loader cam gear 2005 rotates in the positive direction, that is, A direction. When the loader cam gear 2005 rotates, the cartridge is positioned to a proper position, that is, a position where a leader block 2012 can capture a leader pin (not illustrated) by the conventional technique disclosed in Patent Document 1. This operation is the so-called cartridge loading.
When the loading is completed, the leader block 2012 moves from E′ direction to E direction along a guide groove 2004a of a cam plate 2004 (by a power source different from the motor 2006) and is positioned in a leader block picker 2011. As shown in FIG. 7, a protrusion 2012a of the leader block 2012 is engaged with a guide groove 2011a of the leader block picker 2011 and stopped.
Thereafter, the loader cam gear 2005 further rotates and thereby, a capture cam 2005a at the circumferential portion of the loader cam gear 2005 slide-contacts with a second protrusion 2007a of a rotator cam 2007 as shown in FIG. 6 or 9 and the second protrusion 2007a engages with an engagement portion 2005b. Then, as shown in FIG. 8, the rotator cam 2007 rotates in C direction, that is, capture direction against the tension of a spring 2008 serving as urging means. Then, a torsional coil spring 2009 mounted on the rotator cam 2007 also rotates in the C direction. Therefore, a hook portion 2009a of the torsional coil spring 2009 presses a protrusion 2010a of a rotator lever 2010 to rotate the rotator lever 2010 in D direction in FIG. 8.
Because the rotator lever 2010 and leader block picker 2011 are mutually interlocked in rotational operation, the leader block picker 2011 also rotates in the D direction in FIG. 8 in accordance with the rotation of the rotator lever 2010 in the D direction. The leader block 2012 held in the leader block 2011 also rotates in the D direction and as shown in FIG. 10, a leader pin 2001a of the magnetic tape is captured by a hook portion 2012b at the front end of the leader block 2012.
The torsional coil spring 2009 serving as excessive-rotation absorbing means mounted on the rotator cam 2007 is automatically elastically deformed and inflected into a state shown in FIG. 10 when a force equal to or more than a certain force acts. The torsional coil spring 2009 makes only the rotation of the rotator cam 2007 possible while holding attitudes of the leader block picker 2011, rotator lever 2010, and leader block 201 at the present positions. Therefore, even when the rotator cam 2007 excessively rotates or the rotation of the rotator lever 2010 is inhibited because a stack occurs when capturing the leader pin 2001a, it is possible to prevent such problem as damage of the mechanism portion of the leader block picker 2011, rotator lever 2010, leader block 2012, loader cam gear 2005, or rotator cam 2007 and moreover, a problem such as an overload of the motor 2006.
Thus, in the case of the configuration in Patent Document 2, excessive-rotation of the rotator cam 2007 does not become a substantial problem. Therefore, delicate adjustments of the rotation stop position of the loader cam gear 2005 and the rotational value of the rotator cam 2007 at the time of capture become completely unnecessary. Moreover, by previously designing the rotator cam 2007 so that a slight excessive-rotation occurs, for example, by excessive-traveling and rotating the loader cam gear 2005, it is possible to securely prevent a problem that miscapture of a leader pin occurs due to insufficient rotation of the rotator cam 2007.
Patent Document 1 Japanese Patent Laid-Open No. 2001-135003
Patent Document 2 Japanese Patent Application No. 2003-008312
However, in the case of the configuration in the above-described Patent Document 2, the rotator cam gear 2007 and rotator lever 2010 are set between the loader cam gear 2005 and the threader drive gear (not illustrated in FIGS. 6 to 10; refer to FIG. 3). Therefore, it is necessary to widely set the interval between the loader cam gear 2005 and the threader drive gear by the value equivalent to the dimensions of the rotator cam 2007 and the rotator lever 2010. Moreover, because the rotator cam 2007 and rotator lever 2010 rotate in C-C′ direction and D-D′ direction, it is necessary to secure regions in which they rotate. Therefore, in the case of the configuration in the above Patent Document 2, it is difficult to downsize an apparatus.